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    <title>Document</title>
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<body>
    <div>

    </div>
    <script>
        console.log(location.search);  // ?uname = andy
        // 1. 先去掉? substr('起始位置',截取几个字符)
        var params = location.search.substr(1) // uname = andy
        console.log(params);
        // 2. 利用 = 把字符串分割为数组 split('=')
        var arr = params.split('=')
        console.log(arr); //Array(2)
                            // 0: "uname"
                            // 1: "xudiudiu"
        var div = document.querySelector('div')
        div.innerHTML = arr[1]+'欢迎你'
    </script>
</body>
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